Hello!
While taking another pass through the CPU_DYING notifiers, I came upon
the following:
static int tboot_wait_for_aps(int num_aps)
{
unsigned long timeout;
timeout = AP_WAIT_TIMEOUT*HZ;
while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
timeout) {
mdelay(1);
timeout--;
}
if (timeout)
pr_warning("tboot wait for APs timeout\n");
return !(atomic_read((atomic_t *)&tboot->num_in_wfs) ==
num_aps);
}
Questions:
1. Why AP_WAIT_TIMEOUT*HZ? Given the mdelay(), shouldn't this
instead be AP_WAIT_TIMEOUT*1000? The definition of AP_WAIT_TIMEOUT
indicates that it is in seconds.
2. Who changes ->num_in_wfs? Any other CPUs are in stop_machine(),
plus I don't see any assignments to this field. Does the boot
firmware run again to make this change, sort of like SMIs?
I guess that the good news is that I don't seen anything that cares about
stop_machine(). ;-)
Thanx, Paul
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